/**
 * Copyright (C) 2016 Hyphenate Inc. All rights reserved.
 * <p>
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the
 * License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is
 * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing
 * permissions and limitations under the License.
 */
package com.rykj.widget.sidebar;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Paint.Align;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.widget.HeaderViewListAdapter;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SectionIndexer;
import android.widget.TextView;

import com.lcw.library.imagepicker.utils.Util;
import com.rykj.R;


public class EaseSidebar extends View {
    public Paint paint;
    private TextView header;
    private float height;
    private ListView mListView;
    private Context context;

    private int default_color = Color.parseColor("#000000");
    private SectionIndexer sectionIndexter = null;
    private String[] sections;

    public EaseSidebar(Context context, AttributeSet attrs) {
        super(context, attrs);
        this.context = context;
        paint = new Paint(Paint.ANTI_ALIAS_FLAG);
        TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.EaseSidebar, 0, 0);
        if (ta != null) {
            paint.setColor(ta.getColor(R.styleable.EaseSidebar_ease_sidebar_color, default_color));
        }
        ta.recycle();
        init();
    }

    private void init() {
        sections = new String[]{"A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z", "#"};
        //paint = new Paint(Paint.ANTI_ALIAS_FLAG);
        //paint.setColor(Color.parseColor("#8C8C8C"));
        paint.setTextAlign(Align.CENTER);
        paint.setTextSize(Util.sp2px(context, 10));
        paint.setFakeBoldText(true);
    }

    public void setListView(ListView listView) {
        mListView = listView;
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN: {
                if (header == null) {
                    header = (TextView) ((View) getParent()).findViewById(R.id.floating_header);
                }
                setHeaderTextAndscroll(event);
                header.setVisibility(View.VISIBLE);
                setBackgroundResource(R.drawable.ease_sidebar_background_pressed);
                return true;
            }
            case MotionEvent.ACTION_MOVE: {
                setHeaderTextAndscroll(event);
                return true;
            }
            case MotionEvent.ACTION_UP:
                header.setVisibility(View.INVISIBLE);
                setBackgroundColor(Color.TRANSPARENT);
                return true;
            case MotionEvent.ACTION_CANCEL:
                header.setVisibility(View.INVISIBLE);
                setBackgroundColor(Color.TRANSPARENT);
                return true;
        }
        return super.onTouchEvent(event);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        float center = getWidth() / 2;
        height = getHeight() / sections.length;
        for (int i = sections.length - 1; i > -1; i--) {
            canvas.drawText(sections[i], center, height * (i + 1), paint);
        }
    }

    private void setHeaderTextAndscroll(MotionEvent event) {
        if (mListView == null) {
            //check the mListView to avoid NPE. but the mListView shouldn't be null
            //need to check the call stack later
            return;
        }
        String headerString = sections[sectionForPoint(event.getY())];
        header.setText(headerString);
        ListAdapter adapter = mListView.getAdapter();
        if (sectionIndexter == null) {
            if (adapter instanceof HeaderViewListAdapter) {
                sectionIndexter = (SectionIndexer) ((HeaderViewListAdapter) adapter).getWrappedAdapter();
            } else if (adapter instanceof SectionIndexer) {
                sectionIndexter = (SectionIndexer) adapter;
            } else {
                throw new RuntimeException("listview sets adpater does not implement SectionIndexer interface");
            }
        }
        String[] adapterSections = (String[]) sectionIndexter.getSections();
        try {
            for (int i = adapterSections.length - 1; i > -1; i--) {
                if (adapterSections[i].equals(headerString)) {
                    mListView.setSelection(sectionIndexter.getPositionForSection(i));
                    break;
                }
            }
        } catch (Exception e) {
            Log.e("setHeaderTextAndscroll", e.getMessage());
        }

    }

    private int sectionForPoint(float y) {
        int index = (int) (y / height);
        if (index < 0) {
            index = 0;
        }
        if (index > sections.length - 1) {
            index = sections.length - 1;
        }
        return index;
    }

}
